Passing the Smell Test

Clearing the Air in Aquatic Facilities

By Dan Anderson

The first thing anyone notices when walking into an aquatic center is the smell of chlorine. Oh, and the humidity. While swimmers, divers and water dancers might form a bond with these senses, many spectators don't particularly appreciate them.

Chlorine is a necessary disinfectant to protect the health of swimmers and other patrons, but the chloramines created during the disinfection process create quite an odor. What's more, if those chloramines build up in the air, they can pose health risks. Symptoms of over-exposure include irritation to eyes, nose, mouth and/or lungs. In addition to the health of people in the facility, it can do long-term damage to the aquatic center itself.

The humidity of many aquatic centers can make spectators uncomfortable in the stands. Just the thought of getting as wet as the athletes—with their own sweat—might prevent them from even going. While it's not a health threat, it is a problem that needs to be considered by aquatic center managers who want to bring events to their facilities.

While these problems might seem to be unavoidable, there are solutions that can provide relief. High-volume, low-speed (HVLS) fans are one possibility.

Airflow & Destratification

HVLS fans are different from traditional fans in several ways. A typical high-speed ceiling fan spreads air out quickly as it moves away from the fan. The result is that little—if any—air reaches people in the stands or in the pool. High-speed floor fans, meanwhile, create a blast of wind for a relatively small area. They're also noisy and can be disruptive.

Mounted on the ceiling, the advantage of HVLS fans is their ability to move large volumes of air and create a steady, light breeze. As the air gets mixed around in a process called destratification, the odors of chlorine dissipate. A much more uniform air temperature is also created.

The nearly imperceptible light breeze creates an evaporative cooling effect that can reduce the effective temperature by 10 to 12 degrees F. That's a big deal for people watching sporting events in a pool area. Even the athletes can cool off faster and potentially perform better as a result.

HVLS fans come in a variety of sizes, including up to 24 feet wide in diameter. These larger fans can cover an area of 22,000 square feet, effectively replacing up to 20 floor fans.

University of Utah's Ute Natatorium

One aquatic center that learned the value of HVLS fans is the University of Utah's Ute Natatorium. It's one of the leading collegiate swimming and diving venues in the country, regularly hosting NCAA Division I competitions in its six-lane training pool, eight-lane competition pool, and diving well with four diving boards.

Like many pool facilities, the Ute Natatorium had a very noticeable chlorine smell. The natatorium used ceiling fans to control chlorine odors for many years. However, the high-speed ceiling fans were loud and couldn't run continuously. The odors built back up when the fans were off.

Steve Riley, assistant director of events and facilities, and local building consultant Alan Jarvis of Arbon Equipment Corp. honed in on an approach using HVLS fans for the natatorium. After taking measurements of the facility and determining effective smell and humidity levels, Riley and Jarvis decided that they could mitigate both problems with a single, 24-foot diameter, 2-blade fan.

"I was shocked at the difference the fan made," said Riley. "The smell was noticeably different—the chlorine odor was all but gone."

The College of Health noted that chloramine levels in the natatorium were "significantly lower" in readings taken after the fan installation.

Today, more than a year after installation, Riley remains thrilled with the decision to install the fans. He said the complaint about the smell is like the odor itself—gone.

Additional Benefits of HVLS Fans

HVLS fans can even help protect against athletes and spectators from slipping on the pool deck. While they won't be eliminating any puddles that might develop from athletes entering or leaving the pool, HVLS fans can actually make the areas around the pool less slippery by minimizing ceiling-to-floor temperature differentials and increasing the surface evaporation rate.

Also, because destratification moves warmer air toward the ground, the thermostat can be set lower to maintain the same temperature. This can save on energy costs and money.

Important Considerations

There are a number of factors to consider when deciding how and when to use HVLS fans. Fan suppliers can help configure an array of fans, determining the number, size and locations that provide the maximum benefit. They can also offer turnkey installation where on-site resources are not available.

While the basic concept is similar across all HVLS fan manufacturers, fan design and performance are key factors to consider. There are significant differences between manufacturers, including the shape and number of blades, blade tilt, hub construction, blade-to-hub connection and safety features. The performance of different designs will vary in the uniformity of air movement directly below the fan, as well as the height and reach of air movement outward from the fan's diameter.

Other important considerations include ease of installation, fan controls, local representative support, trial program availability and warranties.

Pass the Smell Test

The use of HVLS fans has gained increased attention as a practical and affordable solution to improving air movement and creating overall better environmental control in aquatic centers. They have an ability to help alleviate harsh chlorine smells and provide a cooler perceived temperature.

The use of HVLS fans can greatly improve air quality through better air circulation and are often the most cost-effective way to accomplish this in large open spaces like aquatic centers.